Raffinose Series Oligosaccharides Research Articles

The effect of dehulling of yellow peas and faba beans on the distribution of carbohydrates upon dry fractionation

The impact of dehulling as a pre-treatment for dry fractionation on the distribution of inositol phosphate and the composition and quantity of different carbohydrates in the fine and coarse fractions from yellow peas and faba beans was elucidated. For peas, low molecular weight carbohydrates markedly increased during air classification in the fine fraction whereas for faba beans this tendency was less pronounced. Sucrose and raffinose series oligosaccharides were higher in the coarse and fine fractions, respectively, independently on dehulling pre-treatment. A large part of the insoluble non-starch polysaccharides (NSP) was removed by dehulling and mostly assigned to cellulose. Dehulled faba beans and peas contained similar amount of total and soluble NSP, of which the latter were assigned to pectin and arabinogalactan. In general, dehulling increased the amounts of soluble NSP. Dehulling enriched phytic acid in remaining seeds and it was further enriched with protein in fine fractions. Regarding the aimed product e.g., fine fraction, dehulling gives a slight reduction of non-digestible oligosaccharides and phytic acid in peas but not in faba beans.

Enzymatic hydrolysis and fermentation of soy flour to produce ethanol and soy protein concentrate with increased polyphenols

AbstractThere is a need to effectively concentrate soy protein from defatted soy flour (DSF) while simultaneously valorizing the carbohydrate‐rich byproduct, which would otherwise be a waste. This study aims to evaluate a process developed to produce soy protein concentrates (SPC) by substantially hydrolyzing carbohydrates from DSF with the help of enzymes into water‐soluble saccharides and monomeric sugars, which were simultaneously utilized by Saccharomyces cerevisiae for fermentation into ethanol. The enzyme mixture consisted of cellulase, pectinase, and ‐galactosidase blend. The effect of process time on SPC, overall protein recovery, carbohydrate hydrolysis, yeast growth, ethanol concentration, and total polyphenol concentration (TPC) of SPC and hydrolysate was evaluated. Control and enzymes‐only (EO) systems were maintained in conjunction with the enzymes + yeast (EY) system to individually assess the impact of isoelectric precipitation of soy proteins and enzymatic hydrolysis of carbohydrates without yeasts. After 12.25 h of EY process, 100 g of dry DSF produced 68.45 g dry SPC containing % protein and 384 ml hydrolysate containing mg/ml ethanol. Flatulence‐causing raffinose‐series‐oligosaccharides (RSOs) were completely hydrolyzed. Soluble carbohydrates in the EY treatment were consistently lower than in the control and EO treatment. TPC of SPC prepared by EY treatment increased by 2.5 times compared to the control. Thus, this novel process successfully produced a high‐protein SPC with hydrolyzed RSOs, lower insoluble carbohydrates, high TPC, and a coproduct ethanol.

Valle Agricola Chickpeas: Nutritional Profile and Metabolomics Traits of a Typical Landrace Legume from Southern Italy.

Chickpea (Cicer arietinum L.) from Valle Agricola is a legume cultivated in Southern Italy whose intake is strictly linked to rural traditions. In order to get new biochemical insight on this landrace and to promote its consumption and marketing, nutritional values (moisture content, total proteins, lipids, total and free amino acids) and metabolic traits are deeply investigated. Valle Agricola chickpea is nutritionally rich in proteins (19.70 g/100 g) and essential amino acids (7.12 g/100 g; ~40% of total). Carbohydrates, whose identity was unraveled by means of UHPLC-HR MS/MS analysis, were almost 60% of chemicals. In particular, a di-galactosylglycerol, a pinitol digalactoside, and a galactosylciceritol were found as constitutive, together with different raffinose-series oligosaccharides. Although lipids were the less constitutive compounds, glycerophospholipids were identified, while among free fatty acids linoleic acid (C18:2) was the most abundant, followed by oleic (C18:1) and palmitic (C16:0) acids. Isoflavones and hydroxybenzoic acid derivatives were also detected. Valle Agricola chickpeas showed very good levels of several mineral nutrients, especially magnesium (164 mg/100 g), potassium (748 mg/100 g), calcium (200 mg/100 g), zinc (4.20 mg/100 g) and manganese (0.45 mg/100 g). The boiling process favorably decreases anti-trypsin and anti-chymotrypsin activities, depleting this precious seed of its intrinsic antinutritional factors.

Modeling of lactic acid fermentation of soy formulation with Lactobacillus plantarum HM1.

Lactic acid bacteria alone or with special adjunct probiotic strains are inevitable for the preparation of various specific functional foods. Moreover, because of their growth and metabolism, the final products are preserved for a certain time. Thus, growth dynamics of the lactic acid bacteria of the Fresco DVS 1010 culture ( Lactococcus lactis spp. lactis, Lactococcus lactis spp. cremoris, Streptococcus salivarius spp. thermophilus) during liquid-state fermentation of soya mashes and pH values within the process were analyzed in this study. Although milk is the most typical growth medium for the lactic acid bacteria, presumable viable counts of Fresco culture reached levels 109 CFU ml-1 after 8 h, representing 2-3 log increase in comparison to initial state (specific growth rates ranged from 1.06 to 1.64 h-1). After 21 days of storage period, the pH levels in the products were reduced to 4.50-4.70, representing a decrease of about 1.5-1.7 units. All prepared soybean products contained detectable amounts of raffinose-series oligosaccharides (0.25-0.68 g per 100 g) that were reduced in average by about 30.5% during period of 21 days.

Changes of transport sugar content in different organs of Rehmannia glutinosa

Raffinose series oligosaccharides are the transport and storage sugars of many plants, Rehmannia glutinosa is one of the commonly used Chinese herbal medicines, medicinal parts ist he roots. Root and tuber of R. glutinosa contains stachyose, raffinose and other oligosaccharides, but the study about the process of growth and development of other organs in the non-structural changes in sugar content is rare.In this study, leaves, stems and roots of R. glutinosa were used as materials to analyze the diurnal variation and the changes of sugar content of sucrose, raffinose and stachyose in different organs of R. glutinosa. The results showed that the content of sucrose in R. glutinosa leaves gradually increased from seedling stage.However, the content of stachyose did not change much at the early stage of growth, and the stachyose rapidly increased at the later stage of growth. The raffinose content gradually decreased throughout the growing season, young leaves of R. glutinosa have higher ability to sucrose synthesis than mature leaves, while mature leaf has higher raffinose and stachyose synthesis ability than young leaves. Sucrose and stachyose content in stem gradually increased, while there was little change in raffinose content. The content of raffinose and stachyose in root increased rapidly from the beginning of fast growing period, while the content of sucrose did not change much. The content of sucrose in leaves of R. glutinosa did not change much at day and night, while the daily changes of raffinose and stachyose contents were very obvious. The contents of raffinose and stachyose in daytime were higher than those at night. The content of raffinose in root and stem was not changed much, but the change of stachyose in root, stem and leaf was very obvious, especially in stem and leaf. In summary, the leaf is the main synthetic organ of raffinose, leaves, stems and roots are stachyose synthesis organ. Sucrose, raffinose and stachyose are the major transport forms of carbohydrates in R. glutinosa.

Effect of dietary lupin (Lupinus albus) on the gastrointestinal microbiota composition in broiler chickens and ducks

The purpose of the study was to evaluate the amount of raffinose-series oligosaccharides (RSO) in soybean meal (SBM), whole white lupin seed meal (WLM), sunflower meal (SFM), and rapeseed oil meal (ROM) and to determine whether partial or complete dietary WLM replacement affected the numbers of bacteria in selected groups in the microbiota of broiler chickens and ducks without inducing any weight loss. Total counts of anaerobes, lactobacilli, bifidobacteria, and Escherichia coli in caecal samples from both ducks and broiler chickens, as well as in a crop chyme, in broiler chickens, were determined. Live weights before slaughter were determined. Both broiler chickens and ducks were fed a control diet with SBM (L<sub>0</sub>) or diet containing 50% or 100% WLM as a substitute for SBM (groups L<sub>50</sub> and L<sub>100</sub>, respectively). In comparison with SBM, WLM contained significantly higher amounts of RSO, and the amounts of oligosaccharides in SFM (1.73 ± 0.26 g/100 g) and ROM (1.79 ± 0.14 g/100 g) were negligible compared to those in WLM (8.26 ± 0.14 g/100 g) and SBM (6.96 ± 0.21 g/100 g). The inclusion of lupin in chicken diets did not significantly affect the monitored bacterial groups in crop chyme, but a complete replacement of SBM with WLM (L<sub>100 </sub>group) in chicken diets significantly (P ≤ 0.05) increased the counts of lactobacilli in caecal samples. Partial (L<sub>50 </sub>group) and complete (L<sub>100 </sub>group) lupin supplementation in the duck diet significantly (P ≤ 0.05) increased counts of lactobacilli and bifidobacteria by at least one order of magnitude. E. coli counts in poultry were not affected by changes in diet. The results of our study indicate that partial dietary replacement of SBM with WLM did not significantly affect the live weight of broiler chickens and ducks, but that complete replacement of SBM with WLM may lead to weight loss.

Raffinose-Series Oligosaccharides in Soybean Products

Abstract Soybean foods forming a substantial part of Asian diet have still more expanded into European diet. Raffinose-series oligosaccharides (RSO) are important constituents of soya beans and they can be found also in soybean products. These oligosaccharides can be considered potentially prebiotic for their capability of influencing the composition of the host’s intestinal microbiota. The aim of the present paper was to determine the oligosaccharide content in various soybean products. Enzymatic assay has been used for the determination of oligosaccharides. RSO have been found in all tested samples and their content varied from 0.66 g per 100 g in soybean beverage to 5.59 g per 100 g in first clear soybean flour. Generally, the highest content of RSO has been detected in soybean flour in the average amount of 4.83 g per 100 g. There was no statistically significant difference observed in the amount of oligosaccharides in all four types of soybean flour (P < 0.01). Considerably high amounts of RSO have been found in sweet soybean bars and textured soy protein. Foods as soybean flour and soybean bar ‘Sójový suk’ seem to be effective natural sources of prebiotic oligosaccharides for humans.

Multiple α-galactosidases from Aspergillus foetidus ZU-G1: purification, characterization and application in soybean milk hydrolysis

α-Galactosidase had applied in food and feed industries for hydrolyzing raffinose series oligosaccharides (RO) that are the factors primarily responsible for flatulence upon ingestion of soybean-derived products. The objective of the current work was to purify the α-galactosidase of Aspergillus foetidus ZU-G1 and compared the biochemical and hydrolytic properties of three major α-galactosidase forms (α-gal I, α-gal II and α-gal III). The molecular mass of the purified enzyme as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) was 106.3, 49.7 and 109.9 kDa, respectively. Its optimum reaction temperature was 60 °C and stable below 50 °C. The optimum pH of α-gal I and α-gal III was 5.0 and α-gal II was 4.0. Under 28 °C conditions for 24 h, α-gal I was stable at pH 4.0, α-gal II was stable at pH 6.0, and α-gal III was pH 5.0. α-Galactosidase was completely inhibited by Ag+. CuSO4·5H2O and SDS were powerful inhibitors of α-gal I and α-gal III but had little effect to α-gal II. EDTA did not strongly affect α-gal I and α-gal III, while strongly affect α-gal II. CaCl2·2H2O, MgSO4·7H2O and MnSO4·7H2O were activation for α-gal I, α-gal II and α-gal III. No significant inhibition of enzymes activity was observed in the presence of raffinose, lactose as well as other sugars tested. Synthetic substrate p-nitrophenyl-α-d-galactopyranoside was not preferentially hydrolyzed than natural substrates, such as melibiose, stachyose and raffinose. Under 40 and 50 °C incubation for 1–5 h, the stachyose of soybean milk was degraded by α-gal I, α-gal II and α-gal III and strongly hydrolyzed by α-gal II, and the raffinose of soybean milk was completely hydrolyzed by α-gal II and weakly hydrolyzed by α-gal I and α-gal III. The distinct hydrolytic and biochemical properties of α-gal I, α-gal II and α-gal III further signify the α-galactosidase of A. foetidus ZU-G1 was propitious to soybean milk and related food industry.

Phytic acid and raffinose series oligosaccharides metabolism in developing chickpea seeds

Phytic acid and raffinose series oligosaccharides (RFOs) have anti-nutritional properties where phytic acid chelates minerals and reduces their bioavailability to humans and other animals, and RFOs cause flatulence. Both phytic acid and RFOs cannot be digested by monogastric animals and are released as pollutant-wastes. Efforts are being made to reduce the contents of these factors without affecting the viability of seeds. This will require a thorough understanding of their metabolism in different crops. Biosynthetic pathways of both metabolites though are interlinked but not well described. This study was made on metabolism of these two contents in developing chickpea (Cicer arietinum L cv GL 769) seeds. In this study, deposition of RFOs was found to occur before deposition of phytic acid. A decline in inorganic phosphorus and increase in phospholipid phosphorus and phytic acid was observed in seeds during development. Acid phosphatase was the major phosphatase in seed as well as podwall and its activity was highest at early stage of development, thereafter it decreased. Partitioning of (14) C label from (14) C-glucose and (14) C-sucrose into RFOs and phytic acid was studied in seeds in presence of inositol, galactose and iositol and galactose, which favored the view that galactinol synthase is not the key enzyme in RFOs synthesis.

Levels of nutritional constituents and antinutritional factors in black gram ( Vigna mungo L. Hepper)

A study was conducted on nutritional constituents (total sugars, total proteins, total lipids and starch content) and antinutritional factors such as phenolic compounds, tannins, saponins, phytic acid, trypsin inhibitors and enzymes related to them such as acid- and alkaline phosphatases, α-galactosidase in eleven recommended cultivars and twenty one advance breeding lines of black gram ( Vigna mungo L. Hepper) with an aim to identify genotypes containing high nutritional quality and low antinutritional content. The average content of starch, total soluble sugars, proteins and lipids was around 43.5, 4.84, 22.0 and 1.1%, respectively. Seven genotypes had higher levels of bound fructose contributed by sucrose and raffinose series oligosaccharides. A significant positive correlation was observed among total phenols, o-dihydroxy phenols and flavonols; and among trypsin inhibitors and saponins. The content of phytic acid and activity of trypsin inhibitors showed significant variation among these genotypes. However, not much variation was observed in the content of tannins and saponins. Activities of α-galactosidase, acid- and alkaline phosphatase were found to be related to the content of bound fructose of raffinose series oligosaccharides and phytic acid respectively. Genotypes having higher activity of these enzymes showed lower content of these antinutritional factors. The results showed that the observed diversity in developed cultivars and advance breeding lines could be further used by plant breeders.

Nutritional composition and oligosaccharide contents of preprocessed and fermented African locust bean (<i>Parkia biglobosa</i> benth.) seed during processing

The crude protein, ether extract, glucose, sucrose, total carbohydrate and raffinose-series oligosaccharide contents of African locust bean ( Benth.) seeds were determined following soaking, dehulling, boiling of dehulled seeds for 30 min to hydrate and fermented for 72 h. Mechanically dehulled raw seeds were also obtained from depulped bean seeds with a pair of pliers. There were significant reductions in the levels of raffinose-series oligosaccharides, glucose, sucrose and total carbohydrate of processed seeds, while crude protein and ether extract contents were significantly increased. The raffinoseseries oligosaccharide content decreased from 28.0 ± 2.2 g kg in the raw seeds to 0.1 ± 0.03 g kg in the fermented seeds at 72 h, representing a total reduction of 99.6%. Fermentation gave rise to69.2% and 99.4% reductions in glucose and sucrose contents respectively. The crude protein content was significantly increased (P < 0.001) by fermentation from 270.1 ± 12.3 g kg in the raw seeds to 328.1 ± 4.0 g kg. Also ether extract increased significantly (P < 0.001) from 198.2 ± 11.0 g kg in the raw seeds to 347.3 ± 14.5 g kg in the fermented seeds at 72 h.Keywords: Parkia biglobosa, raffinose-series oligosaccharides,carbohydrates, processing, fermentation

Naturally occurring prebiotic oligosaccharides in poultry feed mixtures

The presence of raffinose series oligosaccharides (RSO) was determined by an enzymic method in three commercially available chicken feed mixtures. All feed mixtures contained RSO at a concentration of 2.1-2.2%. Soya meal was identified as the exclusive source of RSO. Subsequently, the bifidogenic effect of stachyose (main soya bean RSO) was also assigned on the growth of poultry intestinal bifidobacteria. Bifidobacteria were counted in chicken intestinal tract using cultivation and FISH methods. Four out of 6 bifidobacterial strains tested grew significantly better on stachyose than on glucose. It can be thus concluded that chicken feed mixtures naturally contain prebiotic oligosaccharides in the form of RSO in higher levels (>2%) compared with the concentration (usually up to 1%) recommended for artificially added prebiotics. Our results therefore indicate that there is no reason for the supplementation of chicken feed mixtures with prebiotics with bifidogenic properties.

Response surface methodology for optimizing the fermentation medium of alpha-galactosidase in solid-state fermentation

Alpha-galactosidase is applied in food and feed industries for hydrolysing raffinose series oligosaccharides (RO) that are the factors primarily responsible for flatulence upon ingestion of soybean-derived products. The objective of the current work was to develop an optimal culture medium for the production of alpha-galactosidase in solid-state fermentation (SSF) by a mutant strain Aspergillus foetidus. Response surface methodology (RSM) was applied to evaluate the effects of variables, namely the concentrations of wheat bran, soybean meal, KH(2)PO(4), MnSO(4).H(2)O and CuSO(4).5H(2)O on alpha-galactosidase production in the solid substrate. A fractional factorial design (FFD) was firstly used to isolate the main factors that affected the production of alpha-galactosidase and the central composite experimental design (CCD) was then adopted to derive a statistical model for optimizing the composition of the fermentation medium. The experimental results showed that the optimum fermentation medium for alpha-galactosidase production by Aspergillus foetidus ZU-G1 was composed of 8.2137 g wheat bran, 1.7843 g soybean meal, 0.001 g MnSO(4).H(2)O and 0.001 g CuSO(4).5H(2)O in 10 g dry matter fermentation medium. After incubating 96 h in the optimum fermentation medium, alpha-galactosidase activity was predicted to be 2210.76 U g(-1) dry matter in 250 ml shake flask. In the present study, alpha-galactosidase activity reached 2207.19 U g(-1) dry matter. Optimization of the solid substrate was a very important measure to increase enzyme activity and realize industrial production of alpha-galactosidase. The process of alpha-galactosidase production in laboratory scale may have the potential to scale-up.

Comparison of two HPLC systems and an enzymatic method for quantification of soybean sugars

Successful breeding programs need fast and reliable methods for analyzing sugar composition in new soybean ( Glycine max (L.) Merrill) lines. The efficiency to quantify the major sugars, including glucose, fructose, sucrose, raffinose, and stachyose, in five soybean lines with two HPLC systems and an enzymatic procedure were compared. Soluble sugars in soybean were extracted with water at a solvent-to-sample ratio of 5:1 at 50 °C for 15 min, and analyzed by high-performance size exclusion chromatography with refractive index detection (HPSEC-RI), high-performance anion-exchange chromatography with pulsed-amperometric detection (HPAEC-PAD), and a raffinose-series oligosaccharides assay procedure. All three methods produced comparable and reproducible results. The HPAEC-PAD method was more sensitive, faster and capable of separating all five major sugars in soybean with improved peak resolution compared with the HPSEC-RI method, and is recommended for soybean breeding programs. The enzymatic procedure required no expensive instrumentation and less sample preparation, but could not quantify individual raffinose and stachyose.

Sugar signalling and gene expression in relation to carbohydrate metabolism under abiotic stresses in plants

Sucrose is required for plant growth and development. The sugar status of plant cells is sensed by sensor proteins. The signal generated by signal transduction cascades, which could involve mitogen-activated protein kinases, protein phosphatases, Ca 2+ and calmodulins, results in appropriate gene expression. A variety of genes are either induced or repressed depending upon the status of soluble sugars. Abiotic stresses to plants result in major alterations in sugar status and hence affect the expression of various genes by down- and up-regulating their expression. Hexokinase-dependent and hexokinase-independent pathways are involved in sugar sensing. Sucrose also acts as a signal molecule as it affects the activity of a proton-sucrose symporter. The sucrose trans-porter acts as a sucrose sensor and is involved in phloem loading. Fructokinase may represent an additional sensor that bypasses hexokinase phosphorylation especially when sucrose synthase is dominant. Mutants isolated on the basis of response of germination and seedling growth to sugars and reporter-based screening protocols are being used to study the response of altered sugar status on gene expression. Common cis-acting elements in sugar signalling pathways have been identified. Transgenic plants with elevated levels of sugars/sugar alcohols like fructans, raffinose series oligosaccharides, trehalose and mannitol are tolerant to different stresses but have usually impaired growth. Efforts need to be made to have transgenic plants in which abiotic stress responsive genes are expressed only at the time of adverse environmental conditions instead of being constitutively synthesized.

Genetic analysis of seed-soluble oligosaccharides in relation to seed storability of Arabidopsis.

Seed oligosaccharides (OSs) and especially raffinose series OSs (RSOs) are hypothesized to play an important role in the acquisition of desiccation tolerance and consequently in seed storability. In the present work we analyzed the seed-soluble OS (sucrose, raffinose, and stachyose) content of several Arabidopsis accessions and thus identified the genotype Cape Verde Islands having a very low RSO content. By performing quantitative trait loci (QTL) mapping in a recombinant inbred line population, we found one major QTL responsible for the practically monogenic segregation of seed stachyose content. This locus also affected the content of the two other OSs, sucrose, and raffinose. Two candidate genes encoding respectively for galactinol synthase and raffinose synthase were located within the genomic region around this major QTL. In addition, three smaller-effect QTL were identified, each one specifically affecting the content of an individual OS. Seed storability was analyzed in the same recombinant inbred line population by measuring viability (germination) under two different seed aging assays: after natural aging during 4 years of dry storage at room temperature and after artificial aging induced by a controlled deterioration test. Thus, four QTL responsible for the variation of this trait were mapped. Comparison of the QTL genetic positions showed that the genomic region containing the major OS locus did not significantly affect the seed storability. We concluded that in the studied material neither RSOs nor sucrose content had a specific effect on seed storability.

Carbohydrates and their degrading enzymes from native and malted finger millet (Ragi, Eleusine coracana, Indaf-15)

A recently released hybrid ragi, Indaf-15 was germinated up to 96 h at 25°C and the sprouts, drawn at 24 h intervals, were dried, devegetated, powdered and evaluated for malting loss, reducing sugar, free sugar profile, starch content, dietary fibre and an array of carbohydrate-degrading enzymes. Malting loss was maximum (32.5%) at 96 h. The total reducing sugar content increased from 1.44 to 8.36%, whereas the total carbohydrate content decreased from 81 to 58% at 96 h of germination. Analysis of 70% alcohol-soluble sugars revealed glucose, fructose and sucrose in different proportions with respect to germination time. Maltose and maltotriose were detected after 48 and 72 h, respectively. There was a linear decrease in starch content (from 65 to 43%). Activities of amylase and pullulanase were maximum at 72 h whereas those of α– d-glucosidase and 1,3–β– d-glucanase, were maximum at 48 h. Xylanase activity was maximum at 96 h with a concomitant decrease in arabinose to xylose ratio from 1:1 to 1:0.38 in the dietary fibre. α-Galactosidase activity was negligible, which is in tune with a very small amount of raffinose series oligosaccharides. The above results indicated that Indaf-15 is a potential variety for malting purposes as it develops high levels of amylases during germination, and its malt form is a rich source of reducing sugar.

Photosynthetic carbohydrate metabolism in the resurrection plant Craterostigma plantagineum.

The resurrection plant Craterostigma plantagineum (Hochst) is able to survive almost complete tissue dehydration when water is withheld from it, and then can rehydrate rapidly on rewatering. This ability is believed to be the result of the accumulation of sucrose in aerial tissues as a result of metabolism of 2-octulose. In this work the metabolic activity of well-watered Craterostigma plantagineum plants has been investigated. It is shown that Craterostigma makes raffinose series oligosaccharides as a product of photosynthesis and translocates them in the phloem. Evidence is also provided that 2-octulose is a product of photosynthesis and accumulates in the leaves over the light period and is mobilized at night. Thus 2-octulose acts as a temporary storage carbohydrate in leaves during photosynthesis in a similar fashion to starch in most C3 plants. Other potential roles of 2-octulose are discussed. Other than these observations Craterostigma plants are very similar to other C3 plants under these conditions.

Irrigation and Seed Quality Development in Rapid-cycling Brassica: Soluble Carbohydrates and Heat-stable Proteins

Abstract Changes in soluble carbohydrates and heat-stable proteins have been examined in relation to the acquisition of desiccation tolerance and/or potential seed longevity during seed development in rapid-cycling brassica [ Brassica campestris (rapa) L.]. Rates of seed development were moderated by different irrigation regimes. At the early stages, glucose, fructose and sucrose predominated. The raffinose series oligosaccharides accumulated during seed maturation, and occurred earliest in seeds from plants irrigated only until 16 days after pollination. Stachyose content correlated positively, and monosaccharide content correlated negatively, with the ability of seeds to tolerate rapid desiccation and with their potential longevity (the constant K i of the seed viability equation). Similarly, the ratio of oligosaccharide:total sugars provided strong positive correlations with ability to tolerate desiccation and with potential longevity. Most of the heat-stable proteins selected for study accumulated comparatively late, i.e. during maturation drying. The imposition of water stress induced earlier accumulation of heat-stable proteins. The ability to tolerate desiccation was correlated with the content of selected heat-stable proteins, but potential longevity provided stronger correlations. The content of a 58 kDa heat-stable protein provided the strongest positive correlation with potential longevity. A simple multiple regression model of the relations between potential longevity and both the oligosaccharide:total sugar ratio and the 58 kDa heat-stable protein content was developed for all three plant irrigation regimes to show the combined effect of certain sugars and proteins on seed quality. The model suggests that these sugars and proteins are equally likely to be required for seed quality development, and that initially the sugars tend to accumulate at a greater rate than the proteins, but that during maturation drying the heat-stable proteins accumulate at the greater rate.

Natural and synthetic oligosaccharides in broiler chicken diets

This review presents findings on the influence of natural raffinose series oligosaccharides and synthetic (industrial) products on the productivity of broiler chicken. There is evidence of negative effects on animal health and productivity from the use of raffinose series oligosaccharides, but beneficial effects from synthetic oligosaccharides. Part of this contradiction may be due to differences in the chemical nature of the supplements, the level of supplementation or the duration of feeding. The future for synthetic oligosaccharides is bright, but further adoption of natural sources requires a greater understanding of their chemistry to facilitate the production of beneficial compounds and the elimination of detrimental fractions. Most current literature favours the inclusion of various oligosaccharides in the diet. The cost of production could be minimised by the use of natural ingredients which contain oligosaccharides, or by cheap synthetic products, sources of which are highlighted in this review.